Rifamycin C-11 oxime cyclo derivatives effective against drug-resistant microbes

ABSTRACT

The current invention relates to a series of rifamycin derivatives having antimicrobial activities, including activities against drug-resistant microorganisms, specifically, the 3,4-cyclo-rifamycin derivatives having an oxime group at the C-11 position.

BACKGROUND

This application claims priority to U.S. Provisional Patent Application,Ser. No. 60/551,934, entitled “RIFAMYCIN C-11 OXIME CYCLO DERIVATIVESEFFECTIVE AGAINST DRUG-RESISTANT MICROBES” filed on Mar. 10, 2004,having Jing Li and Zhenkun Ma listed as the inventors, the entirecontent of which is hereby incorporated by reference.

This invention relates to rifamycin C-11 oxime derivatives havingantimicrobial activity, their compositions, and methods for treatmentand prevention of microbial infections. One aspect of the currentinvention comprises 3,4-cyclo-11-deoxy-11-oxyiminorifamycins, in whichthe natural rifamycin C-11 keto group is converted to a C-11-oximegroup. Particularly, among the 3,4-cyclo-11-deoxy-11-oxyiminorifamycinsare the C-11 oxime derivatives of rifabutin, rifalazil, rifaximin andrifamycin P origin and their derivatives. The compounds of the currentinvention demonstrate improved antimicrobial and antibacterial activityagainst microbes, including drug-resistant pathogens.

Rifamycins are natural products with potent antimicrobial activity.Examples of the naturally-occurring rifamycins are rifamycin B,rifamycin O, rifamycin R, rifamycin U, rifamycin S, rifamycin SV andrifamycin Y (Brufani et al., 1974). The therapeutic applications of thenaturally-occurring rifamycins are limited due to their poor oralbioavailability, weak activity against Gram-negative pathogens and lowdistribution into the infected tissues. Progress has been made towardidentifying semi-synthetic rifamycin derivatives to address thedeficiencies. Many semi-synthetic rifamycin derivatives with improvedspectrums and pharmacological profiles have been identified. Among thesemi-synthetic compounds, rifampin, rifabutin and rifapetine have beendeveloped into therapeutic agents and are widely used for the treatmentof tuberculosis and other microbial infections (Farr, Rifamycins).

At present, one of the major problems associated with the rifamycinclass of antimicrobial agents is the rapid development of microbialresistance. Mutations in the RpoB gene of RNA polymerase are mainlyresponsible for the high frequency of microbial resistance torifamycins. Consequently, rifamycins are currently used only incombination therapies to minimize the development of resistance to thisclass of drug.

Reference is made to rifamycin derivatives with chemical modificationson the C3 and/or C4 position of the naphthalene ring core, especiallythe therapeutic agents such as rifampin (U.S. Pat. No. 4,002,754),rifalazil (European Patent No. 0190709 B1 and International PatentApplication No. WO 03/051299 A2), rifabutin (U.S. Pat. No. 4,164,499),rifamycin P (European Patent No. 0228606 B1), rifaximin (U.S. Pat. No.4,341,785). Modifications of the ansa chain frequently resulted inrifamycins with reduced antibacterial activity. Modifications on theC-36 position have also been reported (International Patent ApplicationNo. WO 94/28002).

Reference is made to the simple reduction of the C-11 ketone to itsalcohol (Bartolucci et al., 1990). There have been no other reportedchemical modifications on the C-11 position of rifamycin. Compounds ofthe current invention are 11-deoxy-11-oxyiminorifamycin derivativeshaving a cyclic structure at C-3,4 positions of rifamycin. The chemicalmodification involves rifamycin C-11 carbonyl oxygen substitution withnitrogen atom. Because of the trivalent nature of the nitrogen atom,extensive modifications on the C-11 position are now possible. Thecurrent invention constitutes novel compounds having C-11 modificationsthrough preparation of imino derivatives at the C-11 position.

SUMMARY

In its principle embodiment, the current invention provides a series of3,4-cyclo-11-deoxy-11-oxyiminorifamycin derivatives useful asantimicrobial agents, such as antibacterial agents. One aspect of thecurrent invention is a compound having Formula I or Formula II:

or corresponding reduced or oxidized forms, salts, hydrates, prodrugs,and mixtures thereof.

A preferred L₁₁ in the above structures represents a linker groupcomprising any combination of 0 to 5 groups which may be the same ordifferent and are selected from —CR₁R₂—, —NR₃—, —O—, —C(═O)—,—S(═O)₀₋₂—, —C═N—, alkylene, alkenylene, alkynylene, and a bivalent ringcontaining 0 to 3 heteroatoms.

A preferred X₁₁ in the above structures represents —H, —OH, —NH₂, —CO₂H,halo, haloalkyl, —CN, alkyl, substituted alkyl aryl, cycloalkyl,heteroaryl, heterocyclo, or -Q₁₁, wherein Q₁₁ is a structure associatedwith a therapeutic agent. Examples of therapeutic agents includemacrolides, quinolones, beta-lactams, oxazolidinones, tetracyclines, andaminoglycosides.

In Formula I, X and Y, together with the atoms to which they areattached, may form structure III or IV:

In structures III and IV, X₃ represents —O—, —S(O)₀₋₂, or —NR₄—. Forclarity, structures III and IV are illustrated to show a portion of theoriginal structure of Formula I. In particular, structures III and IVshow the C-1 to C-4 positions of the rifamycin of Formula I.

In Formula II, however, X and Y may form structures V or VI:

For clarity, structures V and VI are illustrated to show a portion ofthe original structure of Formula II. In particular, structures V and VIshow the C-1 to C-4 positions of the rifamycin derivative of Formula II.

A preferred Z in the above structures comprises —H or —COCH₂R₁₁, whereinR₁₁ represents —H, —OH, halo, —CN, —CO₂H, —CONR₁₂R₁₃, —NR₁₄R₁₅, —OR₁₆,—S(═O)₀₋₂R₁₇, or -L₂₅Q₂₅. L₂₅ may be absent or represents a heterocyclogroup. Q₂₅ is defined as Q₁₁ above.

In all above structures, R₁, R₂, R₃, R₄, R₅, R₆, R₇, R₈, R₉, R₁₀, R₁₂,R₁₃, R₁₄, R₁₅, R₁₆, and R₁₇ independently are the same or different andare H, alkyl, substituted alkyl, cycloalkyl, aryl, heteroaryl, or aheterocyclo group. In addition, R₁, R₅, R₈, and R₉ may alsoindependently be —OH, —SH, —NH₂, halo, alkoxy, alkylthio, alkylamino, ordialkylamino. When appropriate, one or more of the following threepairs: (i) R₁ and R₂, (ii) R₁₂and R₁₃, and (iii) R₁₄ and R₁₅ may jointogether with their respectively attached atoms to form a ring.

Q₁₁ and Q₂₅ independently represent a structure associated with atherapeutic or antibacterial agent. In further preferred embodiments,Q₁₁ and Q₂₅ independently are the same or different and are any of thestructures VII to XIII:

In these structures, A₁ is CH, CF, or N; A₂ is CH, CF, N, C—CH₃, C—OCH₃,C—OCH₂F, C—OCHF₂, or C—Cl; and A₃ is —CH₂—, —O—, —S—, or —NR₂₅—. R₁₈,R₂₀, R₂₁, R₂₃ and R₂₅ independently are the same or different and are H,alkyl, substituted alkyl, cycloalkyl, aryl, heteroaryl, or a heterocyclogroup. In addition, R₂₀ and R₂₁ together with the carbon to which theyare attached may form a 3-6 membered cycloalkyl ring. R₁₉ is —H, —NH₂,—NO₂, —F, or a C₁₋₆ alkyl. R₂₂ is —H, halo, or an alkyl group. R₂₄ is aheterocyclo group.

In the most preferred embodiments, Q₁₁ and Q₂₅ are the same or differentand are any of the structures shown in FIG. 1.

Another aspect of the current invention comprises a method of treatingmicrobial infection in a subject, wherein the subject is any species ofthe animal kingdom. The microbial infection can be caused by a bacteriumor microorganism. The term “subject” refers more specifically to humanand animals, wherein the animals can be raised for: pets (e.g. cats,dogs, etc.); work (e.g. horses, cows, etc.); food (e.g. chicken, fish,lambs, pigs, etc); and all others known in the art. The method comprisesadministering an effective amount of one or more compounds of thepresent invention to the subject suffering from a microbial infection.The compounds of the present invention are effective againstdrug-resistant microbes and, in particular, rifamycin-resistantmicrobes.

BRIEF DESCRIPTION OF THE DRAWINGS:

FIG. 1 shows a group of structures associated with quinolone classantibacterial agents;

FIG. 2 shows a general synthetic procedure entitled Scheme I; and

FIG. 3 shows a general synthetic procedure entitled Scheme II.

DETAILED DESCRIPTION

Terms:

The following are definitions of terms used in this specification. Theinitial definition provided for a group or term herein applies to thatgroup or term throughout the present specification, individually or aspart of another group, unless otherwise indicated.

The term “acyl” as used herein, refers to a carbonyl (C═O) linked to anorganic group, i.e., R_(d)—C═O, wherein R_(d) may be selected from H,alkyl, alkenyl, substituted alkyl, substituted alkenyl, aryl,heterocyclo, cycloalkyl, or heteroaryl, as defined herein.

The term “alkenyl,” as used herein, refers to a monovalent straight orbranched chain group having 2 to 12 carbon atoms and containing at leastone carbon-carbon double bond. Alkenyl groups of 2 to 6 carbon atoms andhaving one double bond are most preferred. The alkenyl groups of thisinvention can be optionally substituted.

The term “alkenylene,” as used herein, refers to a bivalent straight orbranched chain group containing at least one carbon-carbon double bond.The alkenylene groups of this invention can be optionally substituted.

The term “alkyl,” as used herein, refers to a monovalent, saturated,straight or branched chain hydrocarbon group having 1 to 12 carbonatoms, preferably 1 to 8 carbons. Examples of alkyl group includemethyl, ethyl, propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl,neo-pentyl, and n-hexyl. Lower alkyl groups, that is, alkyl groups of 1to 4 carbons, are most preferred. The alkyl groups of this invention canbe optionally substituted. The term “alkyl” when used in conjunctionwith another group, such as in arylalkyl, refers to a substituted alkylin which at least one of the substituents is the specifically-namedgroup. For example, the term arylalkyl includes benzyl, phenethyl, orany other straight or branched chain alkyl having at least one arylgroup attached at any point of the alkyl chain. As a further example,the term carbamylalkyl includes the group —(CH₂)_(n)—NH—C(═O)alkyl,wherein n is 1 to 12.

The term “alkylene,” as used herein, refers to bivalent saturated,straight or branched chain hydrocarbon groups having 1 to 12 carbonatoms with substituents, preferably 1 to 8 carbon atoms, e.g.,{—CH₂—}_(n), wherein n is 1 to 12, preferably 1-8. Lower alkylenegroups, that is, alkylene groups of 1 to 4 carbon atoms, are mostpreferred. The terms “alkenylene”, “alkynylene”, “arylene” and“heteroarylene” refer to bivalent radicals of alkenyl, alkynyl, aryl andheteroaryl groups, respectively, as defined in this specification.Examples of alkylene groups include methylene, ethylene, propylene,iso-propylene, n-butylene, isobutylene, and n-hexylene. When referenceis made to a substituted alkylene, alkenylene, alkynylene, arylene, orheteroarylene group, these groups are substituted with one to foursubstitutents as defined above for alkyl groups.

The term “alkylamino,” as used herein, refers to an amino group (—NH₂),wherein one hydrogen atom is replaced by an alkyl group. Examples ofalkylamino include methylamino, ethylamino, propylamino, andisopropylamino.

The term “alkylthio,” as used herein, refers to an alkyl or alkenyl orsubstituted alkyl or alkenyl group bonded through a nitrogen (—NR′—)group. For example, the term “aminoalkyl” includes the groups—NR′—C₁₋₁₂alkyl and —NR′—CH₂-aryl. (where R′ is hydrogen, alkyl orsubstituted alkyl as defined above.) “Amino” refers to the group —NH₂.

The term “alkoxy,” as used herein, refers to an alkyl, alkenyl, orsubstituted alkyl or alkenyl group bonded through an oxygen atom (—O—).For example, the term “alkoxy” includes the groups —O—C₁₋₁₂alkyl,—O—C₂₋₈alkenyl, —O—CH₂aryl, and so forth.

The term “alkoxycarbonyl” refers to a group having a carboxy or estergroup (—CO₂) linked to an organic radical, i.e., (—CO₂—R_(d)), whereinR_(d) is as defined above for acyl.

The term “alkynyl,” as used herein, refers to a monovalent straight orbranched chain group of 2 to 12 carbon atoms containing at least onecarbon-carbon triple bond. Examples of alkynyl include ethynyl,propynyl, and butynyl. Alkynyl groups of 2 to 6 carbon atoms and havingone triple bond are most preferred. The alkynyl groups of this inventioncan be optionally substituted.

The term “alkynylene,” as used herein, refers to a bivalent straight orbranched chain group of two to six carbon atoms containing at least onecarbon-carbon triple bond. Examples of alkynylene include ethynylene,propynylene, and butynylene. The alkynylene groups of this invention canbe optionally substituted

The term “aprotic solvent,” as used herein, refers to a solvent that isrelatively inert to protonic activity, i.e., not acting as a protondonor. Examples include hexane, toluene, dichloromethane, ethylenedichloride, chloroform, tetrahydrofuran, N-methylpyrrolidinone, anddiethyl ether.

The term “aryl” as used herein refers to phenyl, biphenyl, 1-naphthyl,2-naphthyl, and anthracenyl, with phenyl being preferred. The term“aryl” includes such rings having zero to five substituents (preferably0-2 substituents), selected from the group consisting of halo, alkyl,substituted alkyl (e.g., trifluoromethyl), alkenyl, substituted alkenyl,alkynyl, nitro, cyano, OH, OR_(d), SR_(d), NR_(d)R_(e), NR_(d)SO₂R_(c),C(═O)H, acyl, —CO₂H, alkoxycarbonyl, carbamyl, sulfonyl, sulfonamide,—OC(═O)R_(d), heteroaryl, heterocyclo, cycloalkyl, phenyl, benzyl,napthyl, including phenylethyl, phenyloxy, and phenylthio, whereinR_(c), R_(d) and R_(e) are defined as above. Additionally, twosubstituents attached to an aryl, particularly a phenyl group, may jointo form a further ring such as a fused or spiro-ring, e.g., cyclopentylor cyclohexyl or fused heterocycle or heteroaryl. When an aryl issubstituted with a further ring, such ring in turn may be substitutedwith one to two of C₀₋₄alkyl optionally substituted with halogen,trifluoromethyl, alkenyl, alkynyl, nitro, cyano, OH, O(alkyl),phenyloxy, benzyloxy, SH, S(alkyl), NH₂, NH(alkyl), N(alkyl)₂, NHSO₂,NHSO₂(alkyl), SO₂(alkyl), SO₂NH₂, SO₂NH(alkyl), CO₂H, CO₂(alkyl),C(═O)H, C(═O)alkyl, C(═O)NH₂, C(═O)NH(alkyl), C(═O)N(alkyl)₂,OC(═O)alkyl, OC(═O)NH₂, OC(═O)NH(alkyl), NHC(═O)alkyl, and NHCO₂(alkyl).

The term “arylene” as used herein refers to bivalent carbocyclicaromatic groups which can be optionally substituted.

The term “benzyl,” as used herein, refers to —CH₂C₆H₅.

The term “carbamyl” refers to a functional group in which a nitrogenatom is directly bonded to a carbonyl, i.e., as in —NR_(e)C(═O)R_(f) or—C(═O)NR_(e)R_(f), wherein R_(e) and R_(f) can be hydrogen, alkyl,substituted alkyl, alkenyl, substituted alkenyl, alkoxy, cycloalkyl,aryl, heterocyclo, or heteroaryl, or they may join to form a ring.

The term “cycloalkyl,” as used herein, refers to fully saturated andpartially unsaturated hydrocarbon rings of 3 to 9 member in size,preferably 3 to 7 carbon atoms. The term “cycloalkyl” includes suchrings having zero to four substituents (preferably 0-2 substituents),selected from the group consisting of halogen, alkyl, substituted alkyl(e.g., trifluoromethyl), alkenyl, substituted alkenyl, alkynyl, nitro,cyano, OH, oxo (═O), OR_(d), SR_(d) NR_(d)R_(e) NR_(c)SO₂,NR_(c)SO₂R_(c), C(═O)H, acyl, —CO₂H, alkoxycarbonyl, carbamyl, sulfonyl,sulfonamide, —OC(═O)R_(d), ═N—OH, ═N—O-alkyl, aryl, heteroaryl,heterocyclo, a 4 to 7 membered carbocyclic ring, and a five or sixmembered ketal, e.g., 1,3-dioxolane or 1,3-dioxane, wherein R_(c), R_(d)and R_(e) are defined as above. The term “cycloalkyl” also includes suchrings having a phenyl ring fused thereto or having a carbon-carbonbridge of 3 to 4 carbon atoms. Additionally, when a cycloalkyl issubstituted-with a ring, i.e., aryl, arylalkyl, heteroaryl,heteroarylalkyl, heterocyclo, heterocycloalkyl, cycloalkylalkyl, or afurther cycloalkyl ring, such ring in turn may be substituted with oneto two of C₀₋₄alkyl optionally substituted with halogen,trifluoromethyl, alkenyl, alkynyl, nitro, cyano, oxo (═O), OH, O(alkyl),phenyloxy, benzyloxy, SH, S(alkyl), NH₂, NH(alkyl), N(alkyl)₂,NHSO₂(alkyl), SO₂(alkyl), SO₂NH₂, SO₂NH(alkyl), CO₂H, CO₂(alkyl),C(═O)H, C(═O)alkyl, C(═O)NH₂, C(═O)NH(alkyl), C(═O)N(alkyl)₂,OC(═O)alkyl, OC(═O)NH₂, OC(═O)NH(alkyl), NHC(═O)alkyl, and NHCO₂(alkyl).

The term “cycloalkylene,” as used herein, refers to bivalent saturatedcarbocyclic groups having three to eight carbons. The cycloalkylenegroups can be optionally substituted.

The term “formyl,” as used herein, refers to —CH(═O).

The term “halogen,” as used herein, refers to fluorine, chlorine,bromine and iodine atoms and the term “halo” refers to —F, —Cl, —Br, and—I as substituent.

The term “haloalkyl” as used herein, refers to a substituted alkylhaving one or more halo substituents. For example, “haloalkyl” includesmono, bi, and trifluoromethyl.

The term “haloalkoxy” means an alkoxy group having one or more halosubstituents. For example, “haloalkoxy” includes —OCF₃.

The term “heteroaryl,” as used herein, refers to substituted andunsubstituted aromatic 5 to 7 membered monocyclic groups, 9 or 10membered bicyclic groups, and 11 to 14 membered tricyclic groups whichhave at least one heteroatom (O, S or N) in at least one of the rings.Each ring of the heteroaryl group containing a heteroatom can containone or two oxygen or sulfur atoms and/or from one to four nitrogen atomsprovided that the total number of heteroatoms in each ring is four orless and each ring has at least one carbon atom. The fused ringscompleting the bicyclic and tricyclic groups may contain only carbonatoms and may be saturated, partially saturated, or unsaturated. Thenitrogen and sulfur atoms may optionally be oxidized and the nitrogenatoms may optionally be quaternized. Heteroaryl groups which arebicyclic or tricyclic must include at least one fully aromatic ring butthe other fused ring or rings may be aromatic or non-aromatic. Theheteroaryl group may be attached at any available nitrogen or carbonatom of any ring. The heteroaryl ring system may contain zero to foursubstituents (preferably 0-2 substituents), selected from the groupconsisting of halo, alkyl, substituted alkyl (e.g., trifluoromethyl),alkenyl, substituted alkenyl, alkynyl, nitro, cyano, OR_(d), SR_(d),NR_(d)R_(e), NR_(d)SO₂R_(c), SO₂R_(d), C(═O)H, acyl, —CO₂H,alkoxycarbonyl, carbamyl, sulfonyl, sulfonamide, —OC(═O)R_(d),heterocyclo, cycloalkyl, aryl, or a monocyclic 4 to 7 membered aromaticring having one to four heteroatoms, including phenylethyl, phenyloxy,and phenylthio, wherein R_(c), R_(d) and R_(e) are defined as above.Additionally, when a heteroaryl is substituted with a further ring,i.e., aryl, arylalkyl, heterocyclo, heterocycloalkyl, cycloalkyl,cycloalkylalkyl, heteroarylalkyl, or a further heteroaryl ring, suchring in turn may be substituted with one to two of C₀₋₄alkyl optionallysubstituted with halogen, trifluoromethyl, alkenyl, alkynyl, nitro,cyano, oxo (═O), OH, O(alkyl), phenyloxy, benzyloxy, SH, S(alkyl), NH₂,NH(alkyl), N(alkyl)₂, NHSO₂(alkyl), SO₂(alkyl), SO₂NH₂, SO₂NH(alkyl),CO₂H, CO₂(alkyl), C(═O)H, C(═O)alkyl, C(═O)NH₂, C(═O)NH(alkyl),C(═O)N(alkyl)₂, OC(═O)alkyl, OC(═O)NH₂, OC(═O)NH(alkyl), NHC(═O)alkyl,and NHCO₂(alkyl).

Exemplary monocyclic heteroaryl groups include pyrrolyl, pyrazolyl,pyrazolinyl, imidazolyl, oxazolyl, isoxazolyl, thiazolyl, thiadiazolyl,isothiazolyl, furanyl, thienyl, oxadiazolyl, pyridyl, pyrazinyl,pyrimidinyl, pyridazinyl, triazinyl and the like.

Exemplary bicyclic heteroaryl groups include indolyl,benzothiazolylbenzodioxolyl, benzoxazolyl, benzothienyl, quinolinyl,tetrahydroisoquinolinyl, isoquinolinyl, benzimidazolyl, benzopyranyl,indolizinyl, benzofuranyl, chromonyl, coumarinyl, benzopyranyl,cinnolinyl, quinoxalinyl, indazolyl, pyrrolopyridyl, furopyridinyl,dihydroisoindolyl, tetrahydroquinolinyl and the like.

Exemplary tricyclic heteroaryl groups include carbazolyl, benzidolyl,phenanthrollinyl, acridinyl, phenanthridinyl, xanthenyl and the like.

The term “heteroarylene,” as used herein, refers to a bivalent cyclicaromatic group having five or six ring atoms wherein at least one ringatom is selected from the group consisting of oxygen, sulfur, andnitrogen, and the remaining ring atoms are carbon. The heteroarylenegroup can be optionally substituted.

The term “heteroatom,” as used herein, refers to oxygen, nitrogen orsulfur atom.

The term “heterocyclo”, “heterocycle” or “heterocyclyl” refers tosubstituted and unsubstituted non-aromatic 3 to 7 membered monocyclicgroups, 7 to 11 membered bicyclic groups, and 10 to 15 memberedtricyclic groups, in which at least one of the rings has at least oneheteroatom (O, S or N). Each ring of the heterocyclo group containing aheteroatom can contain one or two oxygen or sulfur atoms and/or from oneto four nitrogen atoms provided that the total number of heteroatoms ineach ring is four or less, and further provided that the ring containsat least one carbon atom. The fused rings completing bicyclic andtricyclic groups may contain only carbon atoms and may be saturated,partially saturated, or unsaturated. The nitrogen and sulfur atoms mayoptionally be oxidized and the nitrogen atoms may optionally bequaternized. The heterocyclo group may be attached at any availablenitrogen or carbon atom. The heterocyclo ring may contain zero to foursubstituents (preferably 0-2 substituents), selected from the groupconsisting of halo, alkyl, substituted alkyl (e.g., trifluoromethyl),alkenyl, substituted alkenyl, alkynyl, nitro, cyano, oxo (═O), OR_(d),SR_(d), NR_(d)R_(e), NR_(d)SO₂R_(c), SO₂R_(d), C(═O)H, acyl, —CO₂H,alkoxycarbonyl, carbamyl, sulfonyl, sulfonamide, —OC(═O)R_(d), ═N—OH,═N—O-alkyl, aryl, heteroaryl, cycloalkyl, a five or six membered ketal,e.g., 1,3-dioxolane or 1,3-dioxane, or a monocyclic 4 to 7 memberednon-aromatic ring having one to four heteroatoms, wherein R_(c), R_(d)and R_(e) are defined as above. The term “heterocyclo” also includessuch rings having a phenyl ring fused thereto or having a carbon-carbonbridge of 3 to 4 carbon atoms. Additionally, when a heterocyclo issubstituted with a further ring, i.e., aryl, arylalkyl, heteroaryl,heteroarylalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, or afurther heterocyclo ring, such ring in turn may be substituted with oneto two of C₀₋₄ alkyl optionally substituted with halogen,trifluoromethyl, alkenyl, alkynyl, nitro, cyano, oxo (═O), OH, O(alkyl),phenyloxy, benzyloxy, SH, S(alkyl), NH₂, NH(alkyl), N(alkyl)₂,NHSO₂(alkyl), SO₂(alkyl), SO₂NH₂, SO₂NH(alkyl), CO₂H, CO₂(alkyl),C(═O)H, C(═O)alkyl, C(═O)NH₂, C(═O)NH(alkyl), C(═O)N(alkyl)₂,OC(═O)alkyl, OC(═O)NH₂, OC(═O)NH(alkyl), NHC(═O)alkyl, and NHCO₂(alkyl).

Exemplary monocyclic groups include azetidinyl, pyrrolidinyl, oxetanyl,imidazolinyl, oxazolidinyl, isoxazolinyl, thiazolidinyl,isothiazolidinyl, tetrahydrofuranyl, piperidinyl, piperazinyl,2-oxopiperazinyl, 2-oxopiperidinyl, 2-oxopyrrolodinyl, 2-oxoazepinyl,azepinyl, 4-piperidonyl, tetrahydropyranyl, morpholinyl,thiamorpholinyl, thiamorpholinyl sulfoxide, thiamorpholinyl sulfone,1,3-dioxolane and tetrahydro-1,1-dioxothienyl and the like. Exemplarybicyclic heterocyclo groups include diazabicyclooctanes.

The term “heterocycloalkyl” as used herein, refers to a non-aromaticfive-, six- or seven-membered ring or a bi- or tri-cyclic group havingone or more heteroatoms independently selected from oxygen, sulfur, andnitrogen, wherein each 5-membered ring has zero to one double bonds andeach six-membered ring has zero to 2 double bonds. The nitrogen andsulfur heteroatoms can optionally be oxidized, the nitrogen heteroatomcan optionally be quaternized, and any of the above heterocyclic ringscan be fused to an aryl or heteroaryl ring. Representative heterocyclesinclude, but are not limited to: pyrrolidinyl, pyrazolinyl,pyrazolidinyl, imidazolinyl, imidazolidinyl, piperidinyl, piperazinyl,oxazolidinyl, isoxazolidinyl, morpholinyl, thiazolidinyl, morpholinyl,isothiazolidinyl, and tetrahydrofurranyl. The heterocycloalkyl groups ofthis invention can be optionally substituted with one, two, or threesubstituents independently selected from —F, —Cl, —OH, —NO₂, —CN,—C(O)-alkyl, —C(O)-aryl, —C(O)-heteroaryl, —CO₂-alkyl, —CO₂-aryl,—CO₂-heteroaryl, —C(O)NH₂, —C(O)NH-alkyl, —C(O)NH-aryl,—C(O)NH-heteroaryl, —OC(O)-alkyl, —OC(O)-aryl, —OC(O)-heteroaryl,—OC(O)NH₂, —OC(O)NH-alkyl, —OC(O)NH-aryl, —OCONH-heteroaryl,—NHC(O)-alkyl, —NHC(O)-aryl, —NHC(O)-heteroaryl, —NHCO₂-alkyl,—NHCO₂-aryl, —NHCO₂-heteroaryl, —NHC(O)NH₂, —NHC(O)NH-alkyl,—NHC(O)NH-aryl, —NHC(O)NH-heteroaryl, —SO₂-alkyl, —SO₂-aryl,—SO₂-heteroaryl, —SO₂NH₂, —SO₂NH-alkyl, —SO₂NH-aryl, —SO₂NH-heteroaryl,-alkyl, -cycloalkyl, -cycloheteroalkyl, —CF₃, —CH₂OH, —CH₂NH₂, -aryl,-heteroaryl, -benzyl, -benzyloxy, -aryloxy, -heteroaryloxy, -alkoxy,-methoxymethoxy, -methoxyethoxy, -amino, -benzylamino, -arylamino,-heteroarylamino, -alkylamino, -thio, -arylthio, -heteroarylthio,-benzylthio, -alkylthio, and -methylthiomethyl.

The term “heterocycloalkylene” as used herein, refers to a bivalentnon-aromatic five-, six- or seven-membered ring having one or moreheteroatoms independently selected from oxygen, sulfur and nitrogenwherein each 5-membered ring has zero to one double bonds and eachsix-membered ring has zero to 2 double bonds. The heterocycloalkylenegroups of this invention can be optionally substituted.

The term “hydroxyl,” as used herein, refers to —OH.

The term “protecting group,” as used herein, refers to an easilyremovable group to which are known in the art to protect a functionalgroup, such as hydroxyl and amino, against undesirable reaction duringsynthetic procedures and to be selectively removable. The use ofprotecting groups is well-known in the art for protecting groups againstundesirable reactions during a synthetic procedure and many suchprotecting groups are known (T. H. Greene and P. G. M. Wuts, ProtectiveGroups in Organic Synthesis, 2nd edition, John Wiley & Sons, New York,1991).

The term “pharmaceutically acceptable prodrugs,” as used herein refersto the prodrugs of the compounds of the current invention which aresuitable for use in humans and animals with acceptable toxicity,irritation, allergic response, and the like, commensurate with areasonable benefit to risk ratio, and effective for their intended use.

The term “pharmaceutically acceptable salt,” as used herein refers tothose salts which are suitable for use in humans and animals withacceptable toxicity, irritation, and allergic response, etc., and arecommensurate with a reasonable benefit to risk ratio. Pharmaceuticallyacceptable salts are well known in the art. The salts can be prepared insitu during the final step of isolation and purification of thecompounds of the invention or separately prepared by reacting thecompounds of the invention with an acid or base. Examples ofpharmaceutically acceptable salts are salts of an amino group formedwith inorganic acids such as hydrochloric acid, hydrobromic acid,phosphoric acid, and sulfuric acid or with organic acids such as aceticacid, oxalic acid, maleic acid, tartaric acid, citric acid, succinicacid, or malonic acid. Examples of pharmaceutically acceptable saltsinclude salts of an acid group formed with inorganic bases such assodium hydroxide, sodium carbonate, sodium phosphate, etc. Other metalsalts include lithium, potassium, calcium, and magnesium. Additionalpharmaceutically acceptable salts include ammonium cations formed withcounterions such as halide, hydroxide, carboxylate, sulfate, phosphate,nitrate, loweralkyl sulfonate, and aryl sulfonate.

The term “prodrug,” as used herein, represents compounds which can betransformed in vivo to the active parent compounds defined herein.

The term “rifamycin moiety,” as used herein, comprises both its phenolic(hydroquinone) and quinone forms.

The term “ring” refers to substituted or unsubstituted carbocyclicstructures, such as cycloalkyl, aryl as defined above; substituted orunsubstituted heterocyclo, such as heteroaryl or heterocyclyl as definedabove. The term “bivalent ring” refers to the ring having a valency oftwo, such as piperazinyl —N<(CH₂)_(2×2)>N—.

The term “substituent,” as used herein, refers to halogen,trifluoromethyl, alkenyl, alkynyl, nitro, cyano, oxo (═O), OR_(a),SR_(a), NR_(a)R_(b), NR_(a)SO₂R_(c), SO₂R_(c), SO₂NR_(a)R_(b), CO₂R_(a),C(═O)R_(a), C(═O)NR_(a)R_(b), OC(═O)R_(a), OC(═O)NR_(a)R_(b),NR_(a)C(═O)R_(b), NR_(a)CO₂R_(b), ═N—OH, ═N—O-alkyl, aryl, heteroaryl,heterocyclo and cycloalkyl, wherein R_(a), R_(b) and R_(c) are selectedfrom hydrogen, alkyl, alkenyl, cycloalkyl, heterocyclo, aryl, andheteroaryl.

The term “substituted alkyl” refers to an alkyl group as defined abovehaving one to four substituents selected from a group consisting ofhalogen, trifluoromethyl, alkenyl, alkynyl, nitro, cyano, oxo (═O),OR_(a), SR_(a), NR_(a)R_(b), NR_(a)SO₂R_(c), SO₂R_(c), SO₂NR_(a)R_(b),CO₂R_(a), C(═O)R_(a), C(═O)NR_(a)R_(b), OC(═O)R_(a), OC(═O)NR_(a)R_(b),NR_(a)C(═O)R_(b), NR_(a)CO₂R_(b), ═N—OH, ═N—O-alkyl, aryl, heteroaryl,heterocyclo and cycloalkyl, wherein R_(a), R_(b) and R_(c) are selectedfrom hydrogen, alkyl, alkenyl, cycloalkyl, heterocyclo, aryl, andheteroaryl. When a substituted alkyl includes an aryl, heterocyclo,heteroaryl, or cycloalkyl substituent, said ringed systems are asdefined below and thus may in turn have zero to four substituents(preferably 0-2 substituents), also as defined below. When either R_(a),R_(b) or R_(c) is an alkyl or alkenyl, said alkyl or alkenyl mayoptionally be substituted with 1-2 of halogen, trifluoromethyl, nitro,cyano, oxo (═O), OH, O(alkyl), phenyloxy, benzyloxy, SH, S(alkyl), NH₂,NH(alkyl), N(alkyl)₂, NHSO₂(alkyl), SO₂(alkyl), SO₂NH₂, SO₂NH(alkyl),CO₂H, CO₂(alkyl), C(═O)H, C(═O)alkyl, C(═O)NH₂, C(═O)NH(alkyl),C(═O)N(alkyl)₂, OC(═O)alkyl, OC(═O)NH₂, OC(═O)NH(alkyl), NHC(═O)alkyl,and/or NHCO₂(alkyl).

The term “sulfonyl” refers to a sulphoxide group (i.e., —S(O)₁₋₂) linkedto an organic radical R_(c), as defined above.

The term “sulfonamidyl” or “sulfonamido” refers to the group—S(O)₂NR_(e)R_(f), wherein R_(e) and R_(f) are as defined above.Preferably when one of R_(e) and R_(f) is optionally substitutedheteroaryl or heterocycle (as defined below), the other of R_(e) andR_(f) is hydrogen, alkyl, or substituted alkenyl.

The term “unsaturated” is used herein to refer to a ring or group,wherein the ring or group may be fully unsaturated or partiallyunsaturated.

When a subscript is used as in C₁₋₈alkyl, the subscript refers to thenumber of carbon atoms the group may contain. Zero when used in asubscript denotes a bond, e.g., C₀₋₄alkyl refers to a bond or an alkylof 1 to 4 carbon atoms. When used with alkoxy, thioalkyl, or alkylamino(or aminoalkyl), a subscript refers to the number of carbon atoms thatthe group may contain in addition to heteroatoms. Thus, for example,monovalent C₁₋₂alkylamino includes the groups —NH—CH₃, —NH—CH₂—CH₃, and—N—(CH₃)₂. A lower aminoalkyl comprises an aminoalkyl having one to fourcarbon atoms.

The alkoxy, thioalkyl, or aminoalkyl groups may be monovalent orbivalent. By “monovalent” it is meant that the group has a valency(i.e., power to combine with another group) of one, and by “bivalent” itis meant that the group has a valency of two. For example, a monovalentalkoxy includes groups such as —O—C₁₋₁₂alkyl, whereas a bivalent alkoxyincludes groups such as —O—C₁₋₁₂alkylene-, etc.

Abbreviations:

Abbreviations as used herein have the meanings known by one skilled inthe art. Specifically, Ac represents acetyl group, AOC representsallyloxycarbonyl group, BOC represents t-butoxycarbonyl group, Bnrepresents benzyl group, Bu represents butyl group, Bz representsbenzoyl group, Cbz represents benzyloxycarbonyl group, CDI representscarbonyldiimidazole, DCM represents dichloromethane, DMAP represents4-N,N-dimethylaminopyridine, DME represents 1,2-dimethoxyethane, DMFrepresents N,N-dimethylformamide, DMSO represents dimethyl sulfoxide, Etrepresents ethyl group, EtOAc represents ethyl acetate, Me representsmethyl group, MEM represents 2-methoxyethoxymethyl group, MOM representsmethoxylmethyl group, NMP represents N-methylpyrrolidinone, Phrepresents phenyl group, Pr represents propyl group, TEA representstriethylamine, TFA represents trifluoroacetic acid, THF representstetrahydrofuran, TMS, trimethylsilyl group, and Ts representsp-toluenesulfonyl group.

In its principle embodiment, the current invention provides a series of3,4-cyclo-11-deoxy-11-oxyiminorifamycin derivatives useful asantimicrobial agents, such as antibacterial agents. Broadly, one aspectof the present invention comprises a compound having Formula I orFormula II:

-   -   or corresponding reduced or oxidized forms, salts, hydrates,        prodrugs, or mixtures thereof;    -   wherein:    -   L₁₁ comprises any combination of 0 to 5 groups which are        independently the same or different and are selected from        —CR₁R₂—, —NR₃—, —O—, —C(═O)—, —S(═O)₀₋₂—, —C═N—, alkylene,        alkenylene, alkynylene, and a bivalent ring containing 0 to 3        heteroatoms;    -   X₁₁ comprises —H, —OH, —NH₂, —CO₂H, halo, haloalkyl, —CN, alkyl,        substituted alkyl, aryl, cycloalkyl, heteroaryl, heterocyclo, or        -Q₁₁;    -   X and Y, joined together with C-1 to C-4 in Formula I or Formula        II, comprise, structure III or IV, when the compound is the        Formula I:

-   -   -   wherein X₃ is —O—, —S(O)₀₋₂, or —NR₄—, or structure V or VI,            when the compound is the Formula II:

-   -   Z comprises —H or —COCH₂R₁₁, wherein R₁₁ is —H, —OH, halo, —CN,        —CO₂H, —CONR₁₂R₁₃, —NR₁₄R₁₅, —OR₁₆, —S(═)₀₋₂R₁₇, or -L₂₅Q₂₅,        wherein L₂₅ is absent or is a heterocyclo group,        -   wherein R₁, R₅, R₈, and R₉ independently are the same or            different and are —H, —OH, —SH, —NH₂, alkyl, substituted            alkyl, cycloalkyl, aryl, halo, heteroaryl, alkoxy,            alkylthio, alkylamino, dialkylamino, or a heterocyclo group,        -   wherein R₂, R₃, R₄, R₆, R₇, R₁₀, R₁₂, R₁₃, R₁₄, R₁₅, R₁₆,            and R₁₇ independently are the same or different and are H,            alkyl, substituted alkyl, cycloalkyl, aryl, heteroaryl, or a            heterocyclo group, or        -   wherein one or more of the following three pairs: (i) R₁ and            R₂, (ii) R₁₂ and R₁₃, and (iii) R₁₄ and R₁₅ may join            together with the atoms to which they are attached to form a            ring, and        -   wherein Q₁₁ and Q₂₅ are the same or different and are a            therapeutic agent.

In a preferred embodiment, L₁₁ is absent and X₁₁ is —H. In other words,in this preferred embodiment, L₁₁X₁₁ is —H.

In a preferred embodiments, Q₁₁ and Q₂₅ are the same or different andare macrolides, quinolones, beta-lactams, oxazolidinones, tetracyclines,or aminoglycosides.

In further preferred embodiments, Q₁₁ and Q₂₅ are the same or differentand are any of the structures VII to XIII:

wherein A₁ is CH, CF, or N; A₂ is CH, CF, N, C—CH₃, C—OCH₃, C—OCH₂F,C—OCHF₂, or C—Cl; and A₃ is —CH₂—, —O—, —S—, or —NR₂₅—. R₁₈, R₂₀, R₂₁,R₂₃ and R₂₅ independently are the same or different and are H, alkyl,substituted alkyl, cycloalkyl, aryl, heteroaryl, or a heterocyclo group.In addition, R₂₀ and R₂₁, together with the carbon to which they areattached, may form a 3-6 membered cycloalkyl ring. R₁₉ is —H, —NH₂,—NO₂, —F, or a C₁₋₆ alkyl. R₂₂ is —H, halo, or an alkyl group. R₂₄ is aheterocyclo group.

In the more preferred embodiments, Q₁₁ and Q₂₅ are the same or differentand are any of the structures shown in FIG. 1.

In additional more preferred embodiments, the compound is Formula I and,together with C-1 to C-4 of the Formula I, X and Y comprise structureIIIa or IVa:

The compounds of Formulas I and II may form salts which are also withinthe scope of this invention. Reference to a compound of Formulas I andII herein is understood to include reference to salts thereof, unlessotherwise indicated. The term “salt(s),” as employed herein, denotesacidic and/or basic salts formed with inorganic and/or organic acids andbases. In addition, when a compound of Formulas I and II contains both abasic moiety, such as, but not limited to an amine or a pyridine orimidazole ring, and an acidic moiety, such as, but not limited to acarboxylic acid, zwitterions (“inner salts”) may be formed and areincluded within the term “salt(s)” as used herein. Pharmaceuticallyacceptable (i.e., non-toxic, physiologically acceptable) salts arepreferred, although other salts are also useful, e.g., in isolation orpurification steps which may be employed during preparation. Salts ofthe compounds of Formulas I and II may be formed, for example, by mixinga compound of Formulas I and II with an amount of acid or base, such asan equivalent amount, in a medium such as one in which the saltprecipitates or in an aqueous medium followed by lyophilization.

The compounds of Formulas I and II which contain a basic moiety, suchas, but not limited to an amine or a pyridine or imidazole ring, mayform salts with a variety of organic and inorganic acids. Exemplary acidaddition salts include acetates (such as those formed with acetic acidor trihaloacetic acid, for example, trifluoroacetic acid), adipates,alginates, ascorbates, aspartates, benzoates, benzenesulfonates,bisulfates, borates, butyrates, citrates, camphorates,camphorsulfonates, cyclopentanepropionates, digluconates,dodecylsulfates, ethanesulfonates, fumarates, glucoheptanoates,glycerophosphates, hemisulfates, heptanoates, hexanoates, hydrochlorides(formed with hydrochloric acid), hydrobromides (formed with hydrogenbromide), hydroiodides, 2-hydroxyethanesulfonates, lactates, maleates(formed with maleic acid), methanesulfonates (formed withmethanesulfonic acid), 2-naphthalenesulfonates, nicotinates, nitrates,oxalates, pectinates, persulfates, 3-phenylpropionates, phosphates,picrates, pivalates, propionates, salicylates, succinates, sulfates(such as those formed with sulfuric acid), sulfonates (such as thosementioned herein), tartrates, thiocyanates, toluenesulfonates such astosylates, undecanoates, and the like.

The compounds of Formulas I and II which contain an acidic moiety, suchas, but not limited to a carboxylic acid, may form salts with a varietyof organic and inorganic bases. Exemplary basic salts include ammoniumsalts, alkali metal salts such as sodium, lithium, and potassium salts,alkaline earth metal salts such as calcium and magnesium salts, saltswith organic bases (for example, organic amines) such as benzathines,dicyclohexylamines, hydrabamines [formed withN,N-bis(dehydro-abietyl)ethylenediamine], N-methyl-D-glucamines,N-methyl-D-glucamides, t-butyl amines, and salts with amino acids suchas arginine, lysine and the like. Basic nitrogen-containing groups maybe quaternized with agents such as lower alkyl halides (e.g., methyl,ethyl, propyl, and butyl chlorides, bromides and iodides), dialkylsulfates (e.g., dimethyl, diethyl, dibutyl, and diamyl sulfates), longchain halides (e.g., decyl, lauryl, myristyl and stearyl chlorides,bromides and iodides), arylalkyl halides (e.g., benzyl and phenethylbromides), and others.

Compounds of Formulas I and II, and salts thereof, may exist in theirtautomeric form (for example, as an amide or imino ether). All suchtautomeric forms are contemplated herein as part of the presentinvention.

All stereoisomers of the present compounds, such as those, for example,which may exist due to asymmetric carbons, including enantiomeric forms(which may exist even in the absence of asymmetric carbons) anddiastereomeric forms, are contemplated and within the scope of thisinvention. Individual stereoisomers of the compounds of this inventionmay, for example, be substantially free of other isomers, or may beadmixed, for example, as racemates or with all other or other selected,stereoisomers. The chiral centers of the present invention can have theS or R configuration as defined by the IUPAC 1974 Recommendations.

In addition, compounds of Formulas I and II may have prodrug forms. Anycompound that will be converted in vivo to provide the bioactive agent(i.e., a compound of Formulas I and II) is a prodrug within the scopeand spirit of the invention.

For example, pro-drug compounds of Formulas I and II may be carboxylateester moieties. A carboxylate ester may be conveniently formed byesterifying any of the carboxylic acid functionalities found on thedisclosed ring or chain structure(s). Various forms of prodrugs are wellknown in the art (Bundgaard, 1985, and 1992; Bundgaard et al., 1988;Kakeya et al., 1984; Krosgaard-Larsen and Bundgaard, 1991; Widder etal., 1985).

It should further be understood that solvates (e.g., hydrates) of thecompounds of Formulas I and II are also with the scope of the presentinvention. Methods of solvation are generally known in the art.

Compositions:

The compounds of the current invention are rifamycin derivatives ofFormula I and Formula II. Formula I and Formula II are different intheir oxidation states and can be transformed from one to another bymixing with a reductant (ascorbic acid) or oxidant (potassium ferrouscyanide). In one aspect, compounds of the current invention containasymmetric and geometric centers. In some cases, one or more of theasymmetric or geometric centers can be converted to their oppositeconfigurations. These stereoisomers of rifamycin are within the scope ofthe present invention.

EXAMPLE 1

The series of 3,4-cyclo-11-deoxy-11-oxyiminorifamycin derivatives arerepresented by general Formula I or Formula II.

L₁₁ comprises any combination of 0 to 5 groups which can be the same ordifferent and are selected from —CR₁R₂—, —NR₃—, —O—, —C(═O)—,—S(═O)₀₋₂—, —C═N—, alkylene, alkenylene, alkynylene, and a bivalentring. R₁, R₂, and R₃ independently can be the same or different and canbe a variety of groups, including H, alkyl, substituted alkyl,cycloalkyl, aryl, heteroaryl, or a heterocyclo group. R₁ can also be—OH, —SH, alkoxy, alkylthio, alkylamino, or dialkylamino. Whenappropriate, R₁ and R₂ may join together with their respectivelyattached atoms to form a ring.

X₁₁ can be —H, —OH, —NH₂, —CO₂H, halo, haloalkyl, —CN, alkyl,substituted alkyl, aryl, cycloalkyl, heteroaryl, heterocyclo, or Q₁₁,wherein Q₁₁ is any structure associated with an antimicrobial orantibacterial agent. Examples of Q₁₁ include compounds belonging to themacrolide class, the fluoroquinolone class, the non-fluoroquinoloneclass, the oxazolidinone class, the tetracycline class, theaminoglycoside class, the beta-lactam class, the sulfonamide class, thetrimethoprim class, the glycopeptide class, the lipopeptide class, andothers.

In Formula I, X and Y can join together with the C-1 to C-4 positions ofthe rifamycin structure to comprise structure III or IV:

wherein X₃ is —O—, —S(O)₀₋₂, or —NR₄—. R₄, R₅, R₆, and R₇ independentlycan be the same or different and can be a variety of groups, includingH, alkyl, substituted alkyl, cycloalkyl, aryl, heteroaryl, or aheterocyclo group. R₅ can also be —OH, —SH, —NH₂, halo, alkoxy,alkylthio, alkylamino, or dialkylamino.

In Formula II, X and Y can join together with the C-1 to C-4 positionsof the rifamycin structure to comprise structure V or VI:

R₈, R₉, and R₁₀ independently can be the same or different and can be avariety of groups, including H, alkyl, substituted alkyl, cycloalkyl,aryl, heteroaryl, or a heterocyclo group. R₈ and R₉ can alsoindependently be —OH, —SH, alkoxy, alkylthio, alkylamino, ordialkylamino.

Z represents —H or —COCH₂R₁₁, wherein R₁₁ is —H, —OH, halo, —CN, —CO₂H,—CONR₁₂R₁₃, —NR₁₄R₁₅, —OR₁₆, —S(═O)₀₋₂R₁₇, or -L₂₅Q₂₅, wherein L₂₅ isabsent or is a heterocyclo group and wherein Q₂₅ is defined as Q₁₁. Q₁₁and Q₂₅ may be the same or different if any of them is present in thesame molecule. In the natural form, rifamycins have an acetyl group atposition C-25. Chemical or enzymatic hydrolysis of the acetyl groupprovides the de-acetylated compounds wherein Z is a hydrogen atom. Thede-acetylated compounds can be further transformed to compounds where Zis a group of formula —C(O)CH₂R₁₁. R₁₂, R₁₃, R₁₄, R₁₅, R₁₆, and R₁₇ canbe the same or different and can be a variety of groups, such as H,alkyl, substituted alkyl, cycloalkyl, aryl, heteroaryl, or a heterocyclogroup. When appropriate, one or more of the pairs (i) R₁₂ and R₁₃ and(ii) R₁₄ and R₁₅ may join together with their respectively attachedatoms to form a ring.

In the most preferred embodiments, L₁₁ is absent and X₁₁ is —H. In otherwords, in these preferred embodiments, L₁₁X₁₁ is —H.

In a further preferred embodiment, Q₁₁ and Q₂₅ are independently thesame or different and are any of the structures shown in Formulas VII toXIII:

wherein, A₁ is selected from CH, CF, or N; A₂ is selected from CH, CF,N, C—CH₃, C—OCH₃, C—OCH₂F, C—OCHF₂, or C—Cl; A₃ is selected from —CH₂—,—O—, —S—, or —NR₂₅—; R₁₈, R₂₀, R₂₁, R₂₃ and R₂₅ independently are thesame or different and are H, alkyl, substituted alkyl, cycloalkyl, aryl,heteroaryl, or a heterocyclo group; R₂₀ and R₂₁, together with thecarbon to which they are attached, may form a 3-6 membered cycloalkylring; R₁₉ is —H, —NH₂, —NO₂, —F, or a C₁₋₆ alkyl; R₂₂ is —H, halo, or analkyl group; and R₂₄ is a heterocyclo group.

In a further preferred embodiment, Q₁₁ and Q₂₅ are independently thesame or different and are any of the structures shown in FIG. 1.

In most preferred embodiments, the compound is the Formula I, and X andY joined together with the C-1 to C-4 positions of the rifamycin formstructure IIIa or IVa:

with R₅, R₆, and R₇ defined as above.

Preferred compounds of the invention are as follows:11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-5′-(2-methylpropyl)-1-oxo-rifamycinXIV;11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[4-(2-methylpropyl)-1-piperazinyl]-1-oxo-rifamycinVIII;11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(morpholin-4-yl)-1-oxo-rifamycinVIII;11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(4-methyl-1-piperazinyl)-1-oxo-rifamycinVIII;11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(4-ethyl-1-piperazinyl)-1-oxo-rifamycinVIII;11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(4-isopropyl-1-piperazinyl)-1-oxo-rifamycinVIII;11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(4-butyl-1-piperazinyl)-1-oxo-rifamycinVIII;11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(4-cyclohexylmethyl-1-piperazinyl)-1-oxo-rifamycinVIII;11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[4-(1-Methyl-piperidin4-ylmethyl)-1-piperazinyl]-1-oxo-rifamycinVIII;11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[(1,4′)-bipiperidinyl-1′-yl]-1-oxo-rifamycinVIII;11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(3,5-dimethyl-1-piperazinyl)-1-oxo-rifamycinVIII;11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(3-amino-pyrrolidin-1-yl)-1-oxo-rifamycinVIII;11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(pyrrolidin-1-yl)-1-oxo-rifamycinVIII;11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-{4-[2-(2-hydroxy-ethoxy)-ethyl]-piperazin-1-yl}-1-oxo-rifamycinVIII;11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[bis-(2-hydroxy-ethyl)-amino]-1-oxo-rifamycinVIII;11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-methyl-5′-(4-methyl-1-piperazinyl)-1-oxo-rifamycinVIII;11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-5′-(4-isobutyl-1-piperazinyl)-1-oxo-rifamycinVIII;11-Deoxy-11-(4-carboxymethoxyimino)-1′,4-didehydro-1-deoxy-1,4-dihydro-5′-(2-methylpropyl)-1-oxo-rifamycinXIV;11-Deoxy-11-{2-oxo-2-[2-methyl-4-(3-carboxy-1-cyclopropl-2-methoxy-6-fluoro-4-oxo-1,4-dihydroquinolin-7-yl)piperazin-1-yl]ethoxyimino}-1′,4-didehydro-1-deoxy-1,and 4-dihydro-5′-(2-methylpropyl)-1-oxo-rifamycin XIV.

EXAMPLE 2

Pharmaceutical Applications:

The compounds of Formulas I and II disclosed herein can be used in avariety of pharmaceutical applications. In one embodiment, the compoundsmay be used as antimicrobial agents for the treatment of infectiousdisorders that are caused by microbial organisms, such as bacteria.

In one embodiment, compositions, for treating or preventing infectiousdisorders are provided, comprising a compound as disclosed herein incombination with a pharmaceutically acceptable carrier; with one or moreantibiotics of other classes, such as macrolides, fluoroquinolones,oxazolidinones.

In another embodiment, there is provided a dosage amount of a compoundas disclosed herein in an effective amount for the treatment, preventionor alleviation of a disorder, such as an infectious disorder.

The compounds of Formulas I and II can be screened for activity againstdifferent organisms and appropriate dosages may be determined usingmethods available in the art.

The compounds may be used to treat a subject to treat, prevent, orreduce the severity of an infection. Subjects include animals, plants,blood products, cultures and surfaces such as those of medical orresearch equipment, such as glass, needles, tubing and other implanteddevices.

In one embodiment, methods of treating or preventing an infectiousdisorder in a subject, such as a human or other animal subject, areprovided, by administering an effective amount of a compound asdisclosed herein to the subject. In one embodiment, the compound isadministered in a pharmaceutically acceptable form optionally in apharmaceutically acceptable carrier. As used herein, an “infectiousdisorder” is any disorder characterized by the presence of a microbialinfection, such as bacterial infections. Such infectious disordersinclude, for example central nervous system infections, external earinfections, infections of the middle ear, such as acute otitis media,infections of the cranial sinuses, eye infections, infections of theoral cavity, such as infections of the teeth, gums and mucosa, upperrespiratory tract infections, lower respiratory tract infections,genitourinary infections, gastrointestinal infections, gynecologicalinfections, septicemia, bone and joint infections, skin and skinstructure infections, bacterial endocarditis, burns, antibacterialprophylaxis of surgery, and antibacterial prophylaxis inimmunosuppressed patients, such as patients receiving cancerchemotherapy, or organ transplant patients. The compounds andcompositions comprising the compounds can be administered by routes suchas topically, locally or systemically. Systemic application includes anymethod of introducing the compound into the tissues of the body, e.g.,intrathecal, epidural, intramuscular, transdermal, intravenous,intraperitoneal, subcutaneous, sublingual, rectal, and oraladministration. The specific dosage of antimicrobial to be administered,as well as the duration of treatment, may be adjusted as needed.

The compounds of the invention may be used for the treatment orprevention of infectious disorders caused by a variety of bacterialorganisms. Examples include Gram positive and Gram negative aerobic andanaerobic bacteria, including Staphylococci, for example S. aureus;Enterococci, for example E. faecalis; Streptococci, for example S.pneumoniae; Haemophilus, for example H. influenza; Moraxella, forexample M. catarrhalis; and Escherichia, for example E. coli. Otherexamples include Mycobacteria, for example M. tuberculosis;intercellular microbes, for example Chlamydia and Rickettsiae; andMycoplasma, for example M. pneumoniae; and Helicobacter pylori.

Pharmaceutical Compositions:

The pharmaceutical composition of the present invention comprises atherapeutically effective amount of a compound of the current inventionformulated together with one or more pharmaceutically acceptablecarriers. Injectable preparations can be formulated according to theknown art using suitable dispersing or wetting agents and suspendingagents. The sterile injectable preparation can also be a sterileinjectable solution, suspension or emulsion in a nontoxic parenterallyacceptable diluent or solvent, for example, as a solution in1,3-butanediol. Among the acceptable vehicles and solvents that can beemployed are water, Ringer's solution, U.S.P. and isotonic sodiumchloride solution. In addition, sterile, fixed oils are conventionallyemployed as a solvent or suspending medium. The injectable formulationscan be sterilized, for example, by filtration through abacterial-retaining filter, or by incorporating sterilizing agents inthe form of sterile solid compositions which can be dissolved ordispersed in sterile water or other sterile injectable medium prior touse. In order to prolong the effect of a drug, it is often desirable toslow the absorption of the drug through subcutaneous or intramuscularinjection. This can be accomplished by the use of a liquid suspension ofcrystalline or amorphous material with poor water solubility. The rateof absorption of the drug then depends upon its rate of dissolutionwhich, in turn, can depend upon crystal size and crystalline form.Alternatively, delayed absorption of a parenterally administered drugform is accomplished by dissolving or suspending the drug in an oilvehicle. Injectable depot forms are made by forming microencapsulematrices of the drug in biodegradable polymers such aspolylactide-polyglycolide. Depending upon the ratio of drug to polymerand the nature of the particular polymer employed, the rate of drugrelease can be controlled. Examples of other biodegradable polymersinclude poly(orthoesters) and poly(anhydrides). Depot injectableformulations are also prepared by entrapping the drug in liposomes ormicroemulsions that are compatible with body tissues.

Compositions for rectal or vaginal administration are preferablysuppositories which can be prepared by mixing the compounds of thisinvention with suitable non-irritating excipients or carriers such ascocoa butter, polyethylene glycol or a suppository wax which are solidat ambient temperature but liquid at body temperature and therefore meltin the rectum or vaginal cavity and release the active compound.

Liquid dosage forms for oral administration include pharmaceuticallyacceptable emulsions, microemulsions, solutions, suspensions, syrups andelixirs. In addition to the active compounds, the liquid dosage formscan contain inert diluents commonly used in the art such as, forexample, water or other solvents, solubilizing agents and emulsifierssuch as ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethylacetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1,3-butyleneglycol, dimethylformamide, oils, glycerol, tetrahydrofurfuryl alcohol,polyethylene glycols and fatty acid esters of sorbitan, and mixturesthereof. Besides inert diluents, the oral compositions can also includeadjuvants such as wetting agents, emulsifying and suspending agents,sweetening, flavoring, and perfuming agents.

Solid dosage forms for oral administration include capsules, tablets,pills, powders, and granules. In such solid dosage forms, the activecompound is mixed with at least one inert, pharmaceutically acceptableexcipient or carrier such as sodium citrate or dicalcium phosphate andthe following: 1) fillers or extenders such as starches, lactose,sucrose, glucose, mannitol, and silicic acid, 2) binders such as,carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidinone,sucrose, and acacia, 3) humectants such as glycerol, 4) disintegratingagents such as agar-agar, calcium carbonate, potato or tapioca starch,alginic acid, certain silicates, and sodium carbonate, 5) solutionretarding agents such as paraffin, 6) absorption accelerators such asquaternary ammonium compounds, 7) wetting agents such as, cetyl alcoholand glycerol monostearate, 8) absorbents such as kaolin and bentoniteclay, and 9) lubricants such as talc, calcium stearate, magnesiumstearate, solid polyethylene glycols, sodium lauryl sulfate, andmixtures thereof. In the case of capsules, tablets and pills, the dosageform can also comprise buffering agents. Solid compositions of a similartype can also be employed as fillers in soft and hard-filled gelatincapsules using such excipients as lactose or milk sugar as well as highmolecular weight polyethylene glycols and the like. The solid dosageforms of tablets, dragees, capsules, pills, and granules can be preparedwith coatings and shells such as enteric coatings and other coatingswell known in the pharmaceutical formulating art. They can optionallycontain opacifying agents and can also be of a composition that theyrelease the active ingredient only, or preferentially, in a certain partof the intestinal tract, optionally, in a delayed manner. Examples ofembedding compositions which can be used include polymeric substancesand waxes. The active compounds can also be in microencapsulated formwith one or more excipients as noted above.

Dosage forms for topical or transdermal administration of a compound ofthis invention include ointments, pastes, creams, lotions, gels,powders, solutions, sprays, inhalants or patches. The active componentis admixed under sterile conditions with a pharmaceutically acceptablecarrier and any needed preservatives or buffers as can be required.Ophthalmic formulation, ear drops, eye ointments, powders and solutionsare also contemplated as being within the scope of this invention. Theointments, pastes, creams and gels can contain, in addition to an activecompound of this invention, excipients such as animal and vegetablefats, oils, waxes, paraffins, starch, tragacanth, cellulose derivatives,polyethylene glycols, silicones, bentonites, silicic acid, talc and zincoxide, or mixtures thereof.

Powders and sprays can contain, in addition to the compounds of thisinvention, excipients such as lactose, talc, silicic acid, aluminumhydroxide, calcium silicates and polyamide powder, or mixtures of thesesubstances. Sprays can additionally contain customary propellants suchas chlorofluorohydrocarbons.

Transdermal patches have the added advantage of providing controlleddelivery of a compound to the body. Such dosage forms can be made bydissolving or dispensing the compound in the proper medium. Absorptionenhancers can also be used to increase the flux of the compound acrossthe skin. The rate can be controlled by either providing a ratecontrolling membrane or by dispersing the compound in a polymer matrixor gel.

According to the methods of treatment of the present invention,bacterial infections are treated or prevented in a patient such as ahuman or animal by administering to the patient a therapeuticallyeffective amount of a compound of the invention, in such amounts and forsuch time as is necessary to achieve the desired therapeutic effects.The term “therapeutically effective amount” of a compound of theinvention is meant a sufficient amount of the compound to treatbacterial infections, at a reasonable benefit to risk ratio applicableto any medical treatment. It will be understood, however, that the totaldaily usage of the compounds and compositions of the present inventionwill be decided by the attending physician within the scope of soundmedical judgment. The specific therapeutically effective dose level forany particular patient will depend upon a variety of factors includingthe disorder being treated and the severity of the disorder; theactivity of the specific compound employed; the specific compositionemployed; the age, body weight, general health, sex and diet of thepatient; the time of administration, route of administration, and rateof excretion of the specific compound employed; the duration of thetreatment; drugs used in combination or coincidental with the specificcompound employed; and like factors well known in the medical arts.

The total daily dose of the compounds of this invention administered toa human or animals in single or in divided doses can be in amounts, forexample, from 0.1 to 100 mg/kg body weight or preferably from 0.25 to 25mg/kg body weight. Single dose compositions can contain such amounts orsubmultiples thereof to make up the daily dose. In general, treatmentregimens according to the present invention comprise administration toan infected patient of such treatment from about 10 mg to about 2000 mgof the compounds of this invention per day in single or multiple doses.The compounds of current invention can be administered orally, rectally,parenterally, intracisternally, intravaginally, intraperitoneally,topically, bucally, or as an oral or nasal spray.

Biological Activity:

Representative compounds were assayed for antimicrobial activity asfollows: Minimum Inhibitory Concentrations (“MICs”) were determined bythe microbroth dilution method as per NCCLS guidelines (NationalCommittee for Clinical Laboratory Standards. 2000. Methods for dilutionantimicrobial susceptibility tests for bacteria that grow aerobically,5th ed. M7-A5. National Committee for Clinical Laboratory Standards,Wayne, Pa.), except that all growth incubations were conducted at 37° C.Bacterial cultures were tested in the following bacteriological media:S. aureus, S. epidermidis, and E. coli in Cation-Adjusted Mueller-HintonBroth, S. pneumoniae in THY Broth supplemented with 1 mg/mL catalaseunder 5% CO₂ atmosphere, S. pyogenes in THY Broth, E. faecalis in BHIBroth, H. influenzae in BHI Broth supplemented with 0.75 μL of 1 mg/mLNAD and 150 μL of 1 mg/ml hematin per 5 mL, and M. smegmatis inMiddlebrook Broth plus ADC Enrichment. The antimicrobial activity of theexample compounds of the current invention are shown in Table 1.

S. aureus ATCC 2213, S. epidermidis ATCC 12228, S. pneumoniae ATCC6303,S. pyogenes ATCC 19615 and E. faecalis ATCC 29212 arerifampin-susceptible Gram-positive strains. Rifampin exhibits excellentactivity against these organisms with MICs between 0.013 and 1 μg/ml.The compounds of the current invention show further improved activityagainst these strains with MICs as low as 0.0005 μg/ml. In addition,rifampin exhibits low activity against a mycobacterial strain M.smegamatis ATCC 700084 with a MIC 64 μg/ml, while certain compounds ofthe current invention show potent activity against this strain with aMIC 4 μg/ml.

It is to be noted that compounds of the current invention demonstrateexcellent activity against rifampin-resistant organisms. S. aureus ATCC29213 RpoB^(H418Y) is a moderately rifampin-resistant strain with amutation in RpoB gene of RNA polymerase. This mutation results in,however, significantly attenuated MIC for rifampin of 8 μg/ml from itswild type MIC of 0.008 μg/ml. Compounds of the current invention exhibitpotent activity against this resistant strain with a MIC as low as 0.06μg/ml. S. aureus ATCC 29213 RpoB^(D417Y) is a high levelrifampin-resistant strain due to a critical mutation in RpoB gene of RNApolymerase with a MIC is >64 μg/ml for rifampin. Selected compounds ofthe current invention have activity against this highlyrifampin-resistant strain with MICs in the 4 μg/ml level.

Compounds of the current invention are potent againstfluoroquinolone-resistant strains. S. aureus EN1252a gyrA^(S84L)grlA^(S80F) is a quinolone-resistant strain due to double mutations tothe genes confer DNA gyrase and topoisomerase IV. The MIC ofciprofloxacin against this strain is 8 μg/ml. Compounds of the currentinvention demonstrate potent activity against this strain with MICsbetween 0.0005 and 0.125 μg/ml.

TABLE 1 Antimicrobial activity (MIC, mcg/ml) of selected compoundsOrganism rifampin cipro Example 4–22 Staphylococcus aureus rifS 0.0130.25 0.0005–0.125  ATCC29213 Staphylococcus aureus ATCC29213RpoB^(H418Y) rifR 7.8 0.25 <0.06–>62.5 Staphylococcus aureus ATCC29213RpoB^(D417Y) rifR >64 0.25    4–>62.5 Staphylococcus aureus EN1252a^(a)gvrA^(S84L) grlA^(S80F) cipR 0.004 8 0.0005–0.125  Staphylococcusepidermidis rifS 0.03 0.125 0.0005–0.125  ATCC12228 Streptococcuspneumoniae rifS 0.061 1 <0.00006–0.031   ATCC6303 Streptococcus pyogenesrifS 0.013 0.5 <0.00006–0.063   ATCC19615 Enterococcus faecalis rifS 10.5  0.5–31.25 ATCC29212 Haemophilus influenzae rifS 0.24 0.0080.125−8    ATCC10211 Escherichia coli rifS 16 0.03    4–>62.5 ATCC25922Mycobacterium smegmatis rifS 64 0.125    4–>62.5 ATCC700084 ^(a)Forstrain MT1222 see: Ince & Hooper, Antimicrobial Agents and Chemotherapy,2000, 44, 3344–50.

EXAMPLE 3

Synthetic Methods:

The compounds of the current invention can be better understood inconnection with the following general synthetic schemes. The syntheticprocedures shown in Schemes 1 and 2 are for illustration purposes andare not intended to limit the scope of the invention. It will beapparent to one skilled in the art that the compounds of the currentinvention can be prepared by a variety of synthetic routes, includingbut not limited to substitution of appropriate reagents, solvents orcatalysts, change of reaction sequence, and variation of protectinggroups.

The 3,4-cyclo-11-deoxy-11-oxyiminorifamycin derivatives of thisinvention may be prepared by the methods illustrated in Schemes 1 and 2,shown in FIGS. 2 and 3, respectively. Rifabutin, Rifalazil and otherstarting materials are either commercially available or could beprepared according to the known literature. For all schemes andcompounds, the group such as X, Y, Z, A₁, A₂, R, R₁, R₂ and R₃ usedherein is defined as described above for compounds of Formula I orFormula II. It is to be understood that the compounds of Formula I maybe inter-converted between imine-quinone and amine-hydroquinone formsvia an oxidation and reduction process, affected by an oxidant, such aspotassium ferrocyanide, or a reductant, such as ascorbic acid.

As shown in Scheme 1 in FIG. 2, the compounds (2) of Formula I maybeprepared directly from the reaction of compound (1), such as1′,4-didehydro-1-deoxy-1,4-dihydro-5′-(2-methylpropyl)-1-oxo-rifamycinXIV (rifabutin), with NH₂OL₁₁X₁₁, such as hydroxylamine (or its HClsalt, wherein: L₁₁X₁₁ is H) or carboxymethoxyamine (or its HCl salt,wherein: L₁₁X₁₁ is CH₂CO₂H) in a solvent, such as methanol, THF,acetonitrile, in the presence or absence of a base such as pyridine.

As shown in FIG. 3, the compounds of formula (4) may be prepared asdescribed in Scheme II. In general, carboxylic acid in compound (3) maybe first transformed to an active ester by treatment with activatingagents, like N-hydroxyl succinimide and EDC in solvent, like THF in thepresence of a catalyst, like DMAP, then the activated ester may reactwith a nucleophile such as an amine, like morpholine; a thiol, likemethane thiol; an alcohol, like methanol; a nucleophilic antibiotic orits derivatives, like quinolones, oxazolidinones, in solvent, like DMFin the presence or absence of a base such as TEA to provide an amide (4)which is within scope of Formula I.

Specific Compositions:

The compounds of the current invention may be better understood withreference to the following specific examples, which are representativeof some of the embodiments of the invention, and are not intended tolimit the invention.

All starting material used in these specific examples were eitherpurchased from commercial sources or prepared according to publishedprocedures. Operations involving moisture and/or oxygen sensitivematerials are conducted under an atmosphere of nitrogen. Flashchromatography is performed using silica gel 60 as normal phaseadsorbent or C18 silica gel as reverse phase adsorbent. Thin layerchromatography (“TLC”) and preparative thin layer chromatography(“PTLC”) are performed using pre-coated plates purchased from E. Merckand spots are visualized with ultraviolet light followed by anappropriate staining reagent. Nuclear magnetic resonance (“NMR”) spectrawere recorded on a Varian 400 MHz magnetic resonance spectrometer. ¹HNMR chemical shift are given in parts-per million (δ) downfield from TMSusing the residual solvent signal (CHCl₃=δ 7.27, CH₃OH=δ 3.31) asinternal standard. ¹H NMR information is tabulated in the followingformat: number of protons, multiplicity (s, singlet; d, doublet; t,triplet; q, quartet; m, multiplet; td, triplet of doublet; dt, doubletof triplet), coupling constant (s) (J) in hertz. The prefix app isoccasionally applied in cases where the true signal multiplicity isunresolved and prefix br indicates a broad signal. Electro sprayionization mass spectra are recorded on a Finnegan LCQ advantagespectrometer.

EXAMPLE 411-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-5′-(2-methylpropyl)-1-oxo-rifamycinXIV:

Synthesis: To a stirred solution of1′,4-didehydro-1-deoxy-1,4-dihydro-5′-(2-methylpropyl)-1-oxo-rifamycinXIV (rifabutin, 14.5 mg, 0.017 mmol) in MeOH (0.6 mL) was added pyridine(2 μL, 0.025 mmol) and hydroxylamine hydrochloride (2.6 mg, 0.037 mmol).The reaction mixture was allowed to stir 60 hours at room temperature.The solvent was removed in vacuo, and the residue was purified bypreparative thin layer chromatography (10% MeOH/DCM) to give the titlecompound as a red solid (13.5 mg, 91%). ESI MS m/z 862.4 (M+H)⁺; ¹H NMR(400 MHz, CDCl₃) δ 14.19 (s, 1H), 8.94 (s, 1H), 8.33 (s, 1H), 6.42 (dd,J=10.4, 15.6 Hz, 1H), 6.34-6.29 (m, 2H), 5.91 (dd, J=6.4, 15.6 Hz, 1H),5.25 (dd, J=8.4, 12.4 Hz, 1H), 4.62 (d, J=10.4 Hz, 1H),3.69 (d, J=10.0Hz, 1H),3.48 (d, J=6.4 Hz, 1H), 3.43 (s, 1H), 3.34 (dd, J=2.8, 8.4 Hz,1H), 3.09 (s, 3H), 3.02-2.97 (m, 1H), 2.77 (br s, 4H), 2.43-2.38 (m,1H), 2.32 (s, 3H), 2.32-2.27 (m, 2H), 2.05 (s, 3H), 2.04 (s, 3H), 2.00(s, 3H), 1.81.95-1.70 (m, 6H), 1.41-1.35 (m, 1H), 1.04 (d, J=6.8 Hz,3H), 0.96-0.92 (m, 6H), 0.84 (d, J=6.8 Hz, 3H), 0.62 (d, J=6.8 Hz, 3H),-0.04 (d, J=7.2 Hz, 3H).

EXAMPLE 511-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[4-(2-methylpropyl)-1-piperazinyl]-1-oxo-rifamycinVIII:

Synthesis: Step 1.1′,4-Didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[4-(2-methylpropyl)-1-piperazinyl]-1-oxo-rifamycinVIII (rifalazil): The title compound was prepared by using the methoddisclosed in Chem. Pharm. Bull., vol. 41, p. 148, 1993. The titlecompound was obtained as a blue solid. All the other rifalazil-relatedcompounds used herein were also prepared by a similar manner.

Step 2.11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[4-(2-methylpropyl)-1-piperazinyl]-1-oxo-rifamycinVIII: The title compound was prepared by following the same procedure asdescribed for the preparation of example 1 except1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[4-(2-methylpropyl)-1-piperazinyl]-1-oxo-rifamycinVIII (rifalazil) was used in place of1′,4-didehydro-1-deoxy-1,4-dihydro-5′-(2-methylpropyl)-1-oxo-rifamycinXIV (rifabutin). The title compound was obtained as a blue solid. ESI MSm/z 956.3 (M+H)⁺.

EXAMPLE 6

11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(morpholin-4-yl)-1-oxo-rifamycinVIII:

Synthesis: The title compound was prepared by following the sameprocedure as described for the preparation of Example 5 except1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(morpholin-4-yl)-1-oxo-rifamycinVIII was used in place of1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[4-(2-methylpropyl)-1-piperazinyl]-1-oxo-rifamycinVIII (rifalazil). The title compound was obtained as a blue solid. ESIMS m/z 901.1 (M+H)⁺.

EXAMPLE 711-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(4-methyl-i-piperazinyl)-1-oxo-rifamycinVIII:

Synthesis: The title compound was prepared by following the sameprocedure as described for the preparation of Example 5 except1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(4-methyl-1-piperazinyl)-1-oxo-rifamycinVIII was used in place of1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[4-(2-methylpropyl)-1-piperazinyl]-1-oxo-rifamycinVIII (rifalazil). The title compound was obtained as a blue solid. ESIMS m/z 914.2 (M+H)⁺.

EXAMPLE 811-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(4-ethyl-1-piperazinyl)-1-oxo-rifamycinVIII:

Synthesis: The title compound was prepared by following the sameprocedure as described for the preparation of Example 5 except1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(4-ethyl-1-piperazinyl)-1-oxo-rifamycinVIII was used in place of1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[4-(2-methylpropyl)-1-piperazinyl]-1-oxo-rifamycinVIII (rifalazil). The title compound was obtained as a blue solid. ESIMS m/z 928.2 (M+H)⁺.

EXAMPLE 911-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(4-isopropyl-1-piperazinyl)-1-oxo-rifamycinVIII:

Synthesis: The title compound was prepared by following the sameprocedure as described for the preparation of Example 5 except1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(4-isopropyl-1-piperazinyl)-1-oxo-rifamycinVIII was used in place of1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[4-(2-methylpropyl)-1-piperazinyl]-1-oxo-rifamycinVIII (rifalazil). The title compound was obtained as a blue solid. ESIMS m/z 942.2 (M+H)⁺.

EXAMPLE 1011-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(4-butyl-1-piperazinyl)-1-oxo-rifamycinVIII:

Synthesis: The title compound was prepared by following the sameprocedure as described for the preparation of Example 5 except1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(4-butyl-1-piperazinyl)-1-oxo-rifamycinVIII was used in place of1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[4-(2-methylpropyl)-1-piperazinyl]-1-oxo-rifamycinVIII (rifalazil). The title compound was obtained as a blue solid. ESIMS m/z 956.2 (M+H)⁺.

EXAMPLE 1111-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(4-cyclohexylmethyl-1-piperazinyl)-1-oxo-rifamycinVIII:

Synthesis: The title compound was prepared by following the sameprocedure as described for the preparation of Example 5 except1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(4-cyclohexylmethyl-1-piperazinyl)-1-oxo-rifamycinVIII was used in place of1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[4-(2-methylpropyl)-1-piperazinyl]-1-oxo-rifamycinVIII (rifalazil). The title compound was obtained as a blue solid. ESIMS m/z 996.3 (M+H)⁺.

EXAMPLE 1211-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5V-[4-(1-Methyl-piperidin-4-ylmethyl)-1-piperazinyl]-1-oxo-rifamycin VII:

Synthesis: The title compound was prepared by following the sameprocedure as described for the preparation of Example 5 except1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[4-(1-Methyl-piperidin-4-ylmethyl)-1-piperazinyl]-1-oxo-rifamycinVIII was used in place of1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[4-(2-methylpropyl)-1-piperazinyl]-1-oxo-rifamycinVIII (rifalazil). The title compound was obtained as a blue solid. ESIMS m/z 1011.3 (M+H)⁺.

EXAMPLE 1311-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[(1,4′)-bipiperidinyl-1′-yl]-1-oxo-rifamycinVIII:

Synthesis: The title compound was prepared by following the sameprocedure as described for the preparation of Example 5 except1′,4-didehydro-1-deoxy-1,4-dihydro-5′-[(1,4′)-bipiperidinyl-1′-yl]-1-oxo-rifamycinVIII was used in place of1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[4-(2-methylpropyl)-1-piperazinyl]-1-oxo-rifamycinVIII (rifalazil). The title compound was obtained as a blue solid. ESIMS m/z 982.4 (M+H)⁺.

EXAMPLE 1411-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(3,5-dimethyl-1-piperazinyl)-1-oxo-rifamycinVIII:

Synthesis: The title compound was prepared by following the sameprocedure as described for the preparation of Example 5 except1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(3,5-dimethyl-1-piperazinyl)-1-oxo-rifamycinVIII was used in place of1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[4-(2-methylpropyl)-1-piperazinyl]-1-oxo-rifamycinVIII (rifalazil). The title compound was obtained as a blue solid. ESIMS m/z 928.2 (M+H)⁺.

EXAMPLE 1511-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(3-amino-pyrrolidin-1-yl)-1-oxo-rifamycinVIII:

Synthesis: The title compound was prepared by following the sameprocedure as described for the preparation of Example 5 except1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(3-amino-pyrrolidin-1-yl)-1-oxo-rifamycinVIII was used in place of1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[4-(2-methylpropyl)-1-piperazinyl]-1-oxo-rifamycinVIII (rifalazil). The title compound was obtained as a blue solid. ESIMS m/z 900.2 (M+H)⁺.

EXAMPLE 1611-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(pyrrolidin-1-yl)-1-oxo-rifamycinVIII:

Synthesis: The title compound was prepared by following the sameprocedure as described for the preparation of Example 5 except1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(pyrrolidin-1-yl)-1-oxo-rifamycinVIII was used in place of1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[4-(2-methylpropyl)-1-piperazinyl]-1-oxo-rifamycinVIII (rifalazil). The title compound was obtained as a blue solid. ESIMS m/z 869.2 (M+H)⁺.

EXAMPLE 1711-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-{4-[2-(2-hydroxy-ethoxy)-ethyl]-piperazin-1-yl}-1-oxo-rifamycinVIII:

Synthesis: The title compound was prepared by following the sameprocedure as described for the preparation of Example 5 except1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-{4-[2-(2-hydroxy-ethoxy)-ethyl]-piperazin-1-yl}-1-oxo-rifamycinVIII was used in place of1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[4-(2-methylpropyl)-1-piperazinyl]-1-oxo-rifamycinVIII (rifalazil). The title compound was obtained as a blue solid. ESIMS m/z 988.2 (M+H)⁺.

EXAMPLE 1811-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[bis-(2-hydroxy-ethyl)-amino]-1-oxo-rifamycinVIII:

Synthesis: The title compound was prepared by following the sameprocedure as described for the preparation of Example 5 except1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[bis-(2-hydroxy-ethyl)-amino]-1-oxo-rifamycinVIII was used in place of1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[4-(2-methylpropyl)-1-piperazinyl]-1-oxo-rifamycinVIII (rifalazil). The title compound was obtained as a blue solid. ESIMS m/z 903.2 (M+H)⁺.

EXAMPLE 1911-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-methyl-5′-(4-methyl-1-piperazinyl)-1-oxo-rifamycinVIII:

Synthesis: The title compound was prepared by following the sameprocedure as described for the preparation of Example 5 except1′,4-didehydro-1-deoxy-1,4-dihydro-3′-methyl-5′-(4-methyl-1-piperazinyl)-1-oxo-rifamycinVIII was used in place of1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[4-(2-methylpropyl)-1-piperazinyl]-1-oxo-rifamycinVIII (rifalazil). The title compound was obtained as a blue solid. ESIMS m/z 903.2 (M+H)⁺.

EXAMPLE 20 11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-5′-(4-isobutyl-1-piperazinyl)-1-oxo-rifamycin VIII:

Synthesis: The title compound was prepared by following the sameprocedure as described for the preparation of Example 5 except1′,4-didehydro-1-deoxy-1,4-dihydro-5′-(4-isobutyl-1-piperazinyl)-1-oxo-rifamycinVIII was used in place of1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[4-(2-methylpropyl)-1-piperazinyl]-1-oxo-rifamycinVIII (rifalazil). The title compound was obtained as a blue solid. ESIMS m/z 940.4 (M+H)⁺.

EXAMPLE 2111-Deoxy-11-(4-carboxymethoxyimino)-1′,4-didehydro-1-deoxy-1,4-dihydro-5′-(2-methylpropyl)-1-oxo-rifamycinXIV:

Synthesis: The title compound was prepared by following the sameprocedure as described for Example 4 except carboxymethoxylaminehydrochloride was used in place of hydroxylamine hydrochloride. Thetitle compound was obtained as a red solid. ESI MS m/z 920.3 (M+H)⁺.

EXAMPLE 2211-Deoxy-11-{2-oxo-2-[2-methyl4-(3-carboxy-1-cyclopropl-2-methoxy-6-fluoro-4-oxo-1,4-dihydroquinolin-7-yl)piperazin-1-yl]ethoxyimino}-1′,4-didehydro-1-deoxy-1,4-dihydro-5′-(2-methylpropyl)-1-oxo-rifamycinXIV:

Synthesis: Step 1.11-Deoxy-11-{5-(2,5-dioxo-pyrrolidin-1-yloxycarbonyl-methoxyimino)}-1′,4-didehydro-1-deoxy-1,4-dihydro-5′-(2-methylpropyl)-1-oxo-rifamycinXIV: Starting from 11-deoxy-11-(4-carboxymethoxyimino)-1′,4-didehydro-1-deoxy-1,4-dihydro-5′-(2-methylpropyl)-1-oxo-rifamycin XIV, titlecompound may be prepared by reacting with EDC and N-hydroxy succinimidein THF or DMF in the presence of DMAP as catalyst.

Step 2.11-Deoxy-11-{2-oxo-2-[2-methyl-4-(3-carboxy-1-cyclopropl-2-methoxy-6-fluoro-4-oxo-1,4-dihydroquinolin-7-yl)piperazin-1-yl]ethoxyimino}1′,4-didehydro-1-deoxy-1,4-dihydro-5′-(2-methylpropyl)-1-oxo-rifamycinXIV: The product in step 1 may be converted to the title compound byreacting with1-cyclopropyl-2-methoxy-6-fluoro-4-oxo-7-(3-methyl)-piperazin-1-yl-1,4-dihydroquinoline-3-carboxylicacid (gatifloxacin) in DMF.

One skilled in the art readily appreciates that the disclosed inventionis well adapted to carry out the mentioned and inherent objectives.Linkers, fluorophores, ligands of bacterial ribosome and functionalequivalents thereof, pharmaceutical compositions, treatments, methods,procedures, examples and techniques described herein are presented asrepresentative of the preferred embodiments and are not intended aslimitations of the scope of the invention. Thus, other uses will occurto those skilled in the art that are encompassed within the spirit andscope of the described invention.

REFERENCES CITED

The content of the following documents is hereby incorporated byreference.

U.S. PATENT DOCUMENTS

U.S. Pat. No. 4,002,754

U.S. Pat. No. 4,164,499

U.S. Pat. No. 4,341,785

OTHER PATENT DOCUMENTS

European Patent No. 0190709 B1

European Patent No. 0228606 B1

International Patent Application No. WO 94/28002

International Patent Application No. WO 03/051299 A2

OTHER PUBLICATIONS

-   Bartolucci, C., Cellai, L., Cerrini, S., Lamba, D., Segre, A.,    Brizzi, V., Brufani, M. Helvetica Chimica Acta, 1990, vol.73, pp.    185-190.-   Brufani, M., Cerrini, S., Fedeli, W., Vaciago, A. J. Mol. Biol.    1974, vol. 87, pp.409-435.-   Bundgaard, H. ed.; Design of Prodrugs, Elsevier, 1985.-   Bundgaard, H., et al., Journal of Pharmaceutical Sciences, vol.    77, p. 285, 1988.-   Bundgaard, H., Advanced Drug Delivery Reviews, vol. 8, pp. 1-38,    1992.-   Farr, B. M. Rifamycins, in Principles and Practice of Infectious    Diseases; Mandell, G. L., Bennett, J. E., Dolin, R., Eds.;    Churchhill Livingstone: Pa., pp.348-361.-   Kakeya, N., et. al., Chem Phar Bull, vol.32, p. 692, 1984.-   Krosgaard-Larsen and Bundgaard, H., eds.; A Textbook of Drug Design    and Development, Chapter 5, “Design and Application of Prodrugs,”    by H. Bundgaard, pp. 113-191, 1991.-   Widder, K., et al., eds.; Methods in Enzymology, Academic Press,    1985, vol.42, pp.309-396.

1. A compound of structural Formula I or Formula II:

or pharmaceutically acceptable salts thereof; wherein: L₁₁ is anycombination of 0 to 5 groups which are independently the same ordifferent and are selected from —CR₁R₂—, —NR₃—, —O—, —C(═O)—,—S(═O)₀₋₂—, —C═N—, alkylene, alkenylene, and alkynylene; X₁₁ is —H, —OH,—NH₂, —CO₂H, halo, haloalkyl, —CN, alkyl, aryl, or Q₁₁; X and Y, joinedtogether with C-1 to C-4 of Formula I or Formula II, are, structures IIIor IV, when the compound is Formula I:

wherein X₃ is —O—, —S(O)₀₋₂, or —NR₄—, or structures V or VI, when thecompound is Formula II:

Z is —H or —COCH₂R₁₁, wherein R₁₁ is —H, —OH, halo, —CN, —CO₂H,—CONR₁₂R₁₃, —NR₁₄R₁₅, —OR₁₆, —S(═)₀₋₂R₁₇, or —Q₂₅, wherein R₁, R₅, R₈,and R₉ independently are the same or different and are —H, —OH, —SH,—NH₂, alkyl, aryl, alkoxy, alkylthio, alkylamino, or dialkylamino,wherein R₂, R₃, R₄, R₆, R₇, R₁₀, R₁₂, R₁₃, R₁₄, R₁₅, R₁₆, and R₁₇independently are the same or different and are H, alkyl, or aryl, andwherein Q₁₁ and Q₂₅ independently are the same or different and are anyof the structures:


2. The compound of claim 1, wherein L₁₁X₁₁ is —H.
 3. The compound ofclaim 1, wherein the compound is Formula I, and wherein X and Y, joinedtogether with C-1 to C-4 of Formula I, are structure IIIa or IVa:


4. A method of treating a bacterial infection in a subject, comprisingadministering to the subject an effective amount of the compound ofclaim
 1. 5. The method of claim 4, wherein the bacterial infection iscaused by a drug-resistant bacterium.
 6. A compound having a formula:


7. A compound having a formula11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-5′-(2-methylpropyl)-1-oxo-rifamycinXIV:


8. A compound having a formula11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[4-(2-methylpropyl)-1-piperazinyl]-1-oxo-rifamycinVIII:


9. A compound having a formula11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(morpholin-4-yl)-1-oxo-rifamycinVIII:


10. A compound having a formula11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(4-methyl-1-piperazinyl)-1-oxo-rifamycinVIII:


11. A compound having a formula11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(4-ethyl-1-piperazinyl)-1-oxo-rifamycinVIII:


12. A compound having a formula11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(4-isopropyl-1-piperazinyl)-1-oxo-rifamycinVIII:


13. A compound having a formula11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(4-butyl-1-piperazinyl)-1-oxo-rifamycinVIII:


14. A compound having a formula11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(4-cyclohexylmethyl-1-piperazinyl)-1-oxo-rifamycinVIII:


15. A compound having a formula11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[4-(1-Methyl-piperidin4-ylmethyl)-1-piperazinyl]-1-oxo-rifamycin VIII:


16. A compound having a formula11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[(1,4′)-bipiperidinyl-1′-yl]-1-oxo-rifamycinVIII:


17. A compound having a formula11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(3,5-dimethyl-1-piperazinyl)-1-oxo-rifamycinVIII:


18. A compound having a formula11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(3-amino-pyrrolidin-1-yl)-1-oxo-rifamycinVIII:


19. A compound having a formula11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-(pyrrolidin-1-yl)-1-oxo-rifamycinVIII:


20. A compound having a formula11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-{4-[2-(2-hydroxy-ethoxy)-ethyl]-piperazin-1-yl}-1-oxo-rifamycin VIII:


21. A compound having a formula11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-hydroxy-5′-[bis-(2-hydroxy-ethyl)-amino]-1-oxo-rifamycinVIII:


22. A compound having a formula11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-3′-methyl-5′-(4-methyl-1-piperazinyl)-1-oxo-rifamycinVIII:


23. A compound having a formula11-Deoxy-11-hydroxyimino-1′,4-didehydro-1-deoxy-1,4-dihydro-5′-(4-isobutyl-1-piperazinyl)-1-oxo-rifamycinVIII:


24. A compound having a formula11-Deoxy-11-(4-carboxymethoxyimino)-1′,4-didehydro-1-deoxy-1,4-dihydro-5′-(2-methylpropyl)-1-oxo-rifamycinXIV:


25. A compound having a formula11-Deoxy-11-{2-oxo-2-[2-methyl-4-(3-carboxy-1-cyclopropl-2-methoxy-6-fluoro-4-oxo-1,4-dihydroquinolin-7-yl)piperazin-1-yl]ethoxyimino}-1′,4-didehydro-1-deoxy-1,4-dihydro-5′-(2-methylpropyl)-1-oxo-rifamycinXIV:


26. A pharmaceutical composition, useful as medicament for treatment orprevention of bacterial infections, comprising a therapeuticallyeffective amount of a compound in accordance with claim 1 in combinationwith a pharmaceutically acceptable carrier.
 27. A pharmaceuticalcomposition, useful as a medicament for treatment or prevention ofbacterial infections, comprising a therapeutically effective amount of acompound in accordance with claim 6 in combination with apharmaceutically acceptable carrier.